I believe the correct answer from the choices listed above is option C. If the number of hydrogen ions being pumped into the thylakoid is rapidly decreasing, then less sunlight is being used by photosystem II. Hope this answers the question.
        
             
        
        
        
Answer:
Cell>Tissue>Organ>Organ System>Organism.
 
        
             
        
        
        
Answer:
I would think C, if it is consistent then the results should be reliable!
Explanation:
 
        
             
        
        
        
Gravity is a force that can make things go down hill.